Harvey Gulf newbuild to have Cathelco BWTS

FEBRUARY 9, 2016 — Chesterfield, U.K. based Cathelco is supplying a ballast water treatment (BWT) system for a Rampage 6400 multi-purpose field support vessel (MPFSV) being built by Eastern Shipbuilding Group Inc., for Harvey Gulf International Marine, LLC.

The vessel, the Harvey Stone (Hull 234), with a length of 64.8 m and 18 m beam, is due to be delivered in second quarter 2016.

The Cathelco BWT system is based on a combination of filtration and UV technology and has a capacity of 150m3/hr.

Cathelco's long time agent in New Orleans, Green Marine & Industrial Equipment Co.,Inc., won the order.

The Cathelco system received IMO Type Approval in May 2014 and obtained AMS Acceptance from the U.S. Coast Guard a few months later.

"We are one of the few BWT system manufacturers using UV technology that has no restrictions on the salinities in which ships can operate in U.S. waters," says Peter Smith, sales director of Cathelco. "Our system has been approved and accepted to work in marine, brackish and fresh water, allowing vessels to enter the Great Lakes and other inland waterways."

Cathelco says that its AMS approval recognizes that the system will continue to disinfect heavily silted seawater where UV light transmittance values are as low as 45 percent (75 percent being the value for normal seawater).

"All of these factors, combined with the stringent IMO test procedures, demonstrate our commitment to future proofing the system, so that owners can have confidence in their ballast water treatment system selection," says Mr. Smith.

Cathelco's BWT systems are available with capacities from 34 cu.m/hr to 1,200 cu.m/hr in a single unit.

The system automatically adjusts to different sea water qualities. Unlike systems that simply measure turbidity (amount of suspended sediment), the Cathelco system uses a UVT sensor to measure UV light transmittance – the amount of UV radiation actually passing through the seawater. This is a more reliable parameter for calculating the UV dose as well as ensuring that power is used economically. Stepless power control also ensuring that power is used as economically as possible.

Cathelco says the system's space-saving UV chambers are some of the smallest on the market. Each unit is a twin chamber with only two lamps (100 cu.m/hr per lamp) and is designed to make the sea water flow along one side and then the other – doubling UV exposure. In addition, the manifolds make the water flow in a helix, ensuring that the maximum surface area is exposed to the UV light source.

An innovative system using special cleaning balls is used to remove residue from the quartz sleeves and internal surfaces of the chamber. This means that the system does not use chemicals and there are no mechanical parts to scratch the surface of the sleeves.